Rear Drum Brakes: Dangerous in rain: would drilling help?

[DPK]

I have a '2000 Valkyrie Lehman Predator with drum brakes which I have been reliably advised cannot be converted to disc brakes.

I love the trike. It only has 25,000 miles of which I have put on 18,000 miles during the two years I've owned it. I've got the trike almost rigged out the way I want it.

The only problem is the rear drum brakes when wet. The brakes are dangerous - very dangerous in heavy rain or after riding through standing water.

Returning home from a week long trip recently, I ran into heavy rain about ten miles from home. I tapped the brakes lightly to check them and the road conditions and the rear immediately began locking up and skidding from side to side. I then slowed as much as was safe under freeway conditions by gently downshifting and turning onto lesser travelled streets asap. Even then at slow speeds the lightest touch on the pedal would lock one or the other rear wheel. When I was within 1,000 feet from home, a car pulled out in front of me and I had to jump a curb and stop on grass to avoid a crash.

I previously knew I had a problem after riding through standing water and would simply ride the brake long enough to dry them out. Riding on wet highways during light rains are not a problem beyond the normal somewhat slippery condition of the road surface.

I had never before rode the trike in a really heavy rain. The skidding was not from a wet highway. It most definitely was due to water in the brake drum

The problem is so serious to me that I am considering selling a trike I dearly love.

The he brakes are self-adjusting and the adjustment mechanisms are in proper order; the shoes are at least 75%; the drum surfaces are smooth and he tires are new with less than 5000 miles. The tread design is a rain tire design.

Do do those of you with drum brakes have such a serious problem as I am experiencing?

Would it be possible / practical to purchase a later model Lehman rear axle component with disc brakes and install it on my trike?

Would "drilling" the brake drums solve or diminish the problem?

I have some suspicion that the self-adjusting feature is to blame. Can it be removed if it would help?

Any comments or suggestions would be appreciated.

Dan

[Sidecarbill]

I think the small ford pickups had a similar problem. the bulletin on it said 2 make sure all rubber plugs were in place,and use silicone seal around wheel cylinders and any other openings. Don't know if it would apply in ur case but easy enough 2 do.

[Pegasus1300]

I can't imagine that there is not some way to put disk brakes on that rear end. It might not be a plug and play type situation,but I would do a lot more searching before giving up a ride I really loved. BTW what kit do you have? What rear end does it use? Have you considered putting an IRS rear end underneath? What about a different solid rear end that has disks? Yes any of these suggestions will be expensive but how important is it to keep your Valk?

[steamer]

I have drums on my motortrike kit and have never had the brakes lock up in the rain and we have been through some heavy rain storms. I have a 7 1/2" ford rear end. I have own a lot of cars over the years with drum brakes front and rear and I remember them loosing there ability to work when wet. Always had to ride the brakes to dry them out and give yourself extra stopping room.

[rhino 2]

Just doesn't sound right, When drum brakes get wet they don't lockup the wheels, On the contrary they reduced the stopping power when wet, Are you sure your tires have enough thread, Or maybe their over inflated...

[0pini0nated]

Just doesn't sound right, When drum brakes get wet they don't lockup the wheels, On the contrary they reduced the stopping power when wet.

I side with Sidecarbill & Rhino 2. You don't want to ruin your brake backing plates by drilling holes in them. If they got soaked in a downpour, well . . . that happens. But they depend on friction to work. If you open them up to wet weather, they will fade and leave you with NO rear brakes.

I had drum brakes on my previous XL1200 Lehman Raider (9" Ford drum brakes, as I recall) and they were OK. They didn't have enough weight to auto-adjust the shoes, so they had to be done manually (Lehman mentioned that in the User Manual)

If it were me, I'd have a technician (preferably an older one with drum brake experience) look at the brakes with the drums off. Touchy drum brakes were a sign that someone got the primary and secondary shoes accidentally reversed.

Also, there was an old post in a different forum about swapping Ford-based trike drums brakes for disc brakes.

I don't remember what brand trike it involved, but I could *probably* dig it out if you're going in that direction.

Just my 2¢...

[keepinon]

I never had a problem with grabby brakes on my Valk w/MT SA kit. The only rain related problem was the tires. When I bought the trike used, it had 245/60-15's on the rear. SOB's would hydroplane/lockup when riding on wet/rained on roads. I went all the way down to a 205/75-15 Goodrich tire with nice straight tread. It cured that problem.

I did have fading of the rear brakes if riding thru deep puddles. But just a short time of riding the brakes dried them out, then they worked properly.

MT used the Ford 7.5 rear end with self adjusting brakes. They don't work. As said earlier, there's not enough weight to trigger them.

I removed my self adjusters, it made manually adjusting them a lot easier, you didn't have to fight the adjuster arm on the star wheel. I just carried a brake spoon (tool) in the tool kit, and when the brakes seemed too low, just adjust up a couple of notches. Very easy to do.

In consultation with MT's brake man, he advised me that the master cylinder on the Valk did not move enough brake fluid to operate disc brakes. Grumpy, a member here, did try it on his Valkyrie with less than stellar results. I decided not to try discs.

[kybigmac]

I have a SA MT kit that was installed in 99 on a 93 GW. I've only had it a yr.and a half but it has never locked up in rain since I've had it,and I've been in some downpours!

[ben721364]

<snip> the rear immediately began locking up and skidding from side to side. I then slowed as much as was safe under freeway conditions by gently downshifting and turning onto lesser travelled streets asap. Even then at slow speeds the lightest touch on the pedal would lock one or the other rear wheel. <snip>

Dan

Are you sure that the trike isn't hydroplaning v. the rear brakes locking up? Just a thought...</snip></snip>

[Phu Cat]

Are you sure that the trike isn't hydroplaning v. the rear brakes locking up?

Very good question above.

Would it be worth changing the rear brake shoes to see if that would help?

Phu Cat

[Future Triker]

Based on what you're saying, it sounds as though the rear of the bike is hydroplaning in wet weather. Like the others have said, wet brakes DO NOT stop, much less lock up the rear wheels. What is the tread depth of your tires like? If they are worn down, you may not have enough tread to displace the water during wet weather braking which causes the tire(s) to "float" on the surface of the water. In addition, cheaper tires will also do it too (learned that lesson on a 300ZX twin turbo I used to own).

I'd recommend taking a look at your tires moreso than brakes (long way of saying I agree with the others on here).

[Sidecarbill]

Google ford ranger grabby brakes you'll find plenty. We had this problem on customer pickups. There's a tsb on it.said change bake shoes seal openings. Nuff said good luck!

[DPK]

Thanks, everyone, for the comments & suggestions.

I'm now convinced that the drum brakes can be made to work in an acceptable manner, I'm going to search out someone who knows what needs to be done & have it done.

With regard to particular suggestions or comments; I'm sure I was not experiencing hydroplane, the "drilling" I mentioned was not to the backing plate - I was referring to drilling the swept area of the drums. We used to do this with old sports cars along with milling a diagonal notch across the surface of the shoes - a horizontal version of drilled discs & notched pads.

The he behaviour of my brakes is consistent with leading / trailing shoes being reversed if that is possible or just a simple case of the wrong shoes.

Now on that I know there is light at the end of the tunnel, I'll figure it out & report.

Thanks everyone.

Dan

- - - Updated - - -

Thanks, everyone, for the comments & suggestions.

I'm now convinced that the drum brakes can be made to work in an acceptable manner, I'm going to search out someone who knows what needs to be done & have it done.

With regard to particular suggestions or comments; I'm sure I was not experiencing hydroplane, the "drilling" I mentioned was not to the backing plate - I was referring to drilling the swept area of the drums. We used to do this with old sports cars along with milling a diagonal notch across the surface of the shoes - a horizontal version of drilled discs & notched pads.

The he behaviour of my brakes is consistent with leading / trailing shoes being reversed if that is possible or just a simple case of the wrong shoes.

Now on that I know there is light at the end of the tunnel, I'll figure it out & report.

Thanks everyone.

Dan

[CrystalPistol]

Just doesn't sound right, When drum brakes get wet they don't lockup the wheels, On the contrary they reduced the stopping power when wet, Are you sure your tires have enough thread, Or maybe their over inflated...

That's been my experience ..... and I have had quite a few vehicles with nothing but drums back in the day. Back then, I had been known to ford a creek or otherwise get in deeper water and just like disc brakes, wet drums don't stop as well wet as dry.

Our Lehman also has Ford 9" drum rear brakes and the beauty of drums .... besides self energizing .... is their friction surfaces will stay dry unless and until I ford a creek with it ..... which I don't. I've had it in some torrential rains when caught out and noticed that the front brakes lost effectiveness, but them rears worked as good as ever ..... which could lead someone to step harder looking for more frt brakes and accidently locking the rears or one rear.

One thing that will cause a rear drum brake to grab is a leaking axle seal.

[DPK]

I finally raised the trike and put it on stands and discovered that one of the adjustment plush was missing. Also, based on the long travel of the parking brake before it stops, I'm sure the brakes need adjusting.

Im going to pull the drums while it is raised & see what is going on. When reinstalling the drums, will it work to adjust the shoes until making contact with the drums and back off the same number of turns on each side so as to synchronize both sides?

dan

[Gorilla]

I used to back the adjuster off so that I had the same light drag on both wheels.

[keepinon]

......

Im going to pull the drums while it is raised & see what is going on. When reinstalling the drums, will it work to adjust the shoes until making contact with the drums and back off the same number of turns on each side so as to synchronize both sides?

dan

After I did major work on my brakes, I would adjust them to full lock, while turning the tire, then back off the same number of clicks on each side. Seemed to keep me braking straighter in a lock-up situation. The aim was to have the same amount of piston travel on each side.

Some folks can do it by ear. My hearing isn't that good.

[kybigmac]

After I did major work on my brakes, I would adjust them to full lock, while turning the tire, then back off the same number of clicks on each side. Seemed to keep me braking straighter in a lock-up situation. The aim was to have the same amount of piston travel on each side.

Some folks can do it by ear. My hearing isn't that good.

That's pretty much the way I was taught to adjust brakes.

[CrystalPistol]

I finally raised the trike and put it on stands and discovered that one of the adjustment plush was missing. Also, based on the long travel of the parking brake before it stops, I'm sure the brakes need adjusting.

Im going to pull the drums while it is raised & see what is going on. When reinstalling the drums, will it work to adjust the shoes until making contact with the drums and back off the same number of turns on each side so as to synchronize both sides?

dan

When I install my drums, I first tighten up the adjuster just until I can slip the drum back in place. Usually there is a less worn area of drum that the shoes have to pass. Once installed and wheels in place and tight ..... while wheels are still off the floor and trike up on stands, trans in neutral ..... I slide under the trike at rear and pop out plugs and rotate the tire with one hand while making slow one click adjustments tightening the adjuster up until I start hearing the drum scraping the shoe's surface .... but while wheel is still mostly easy to turn.

Properly adjusted, there'll be some places where some slight resistance will be felt maybe but mostly, wheel free to turn by one hand and only slight scraping noises heard as the brake shoe's skim the drum just ever so slightly.

To tighten the adjusters, the star wheel always turns inwards at top, out at bottom. ie: Facing towards front of trike from rear like the trike ... the left side adjuster turns CW to tighten, the right side one CCW to tighten. This means brake spoon in hole and tip in contact with star and push hand up.

If you go too far and suddenly that brake gets tight consistently, you'll need to insert a pick or small screw driver to push the adjustment lever away from the star while you back it off a tooth or two .... or three.

Put plugs back in backing plates.

I also have a 10 psi residual pressure valve in my rear brake line between master cylinder and tee to rear brakes to keep seals full but brake springs will still over ride it to pull shoes back. I get a better pedal with it.

Do not use a 10 psi RPV on disc brakes as they have no return springs .... use a 3 psi version on disc if you want.